For example, an electronic device such as a mobile phone includes a casing including an upper casing and a lower casing each composed of a synthetic resin, a plurality of component built-in modules that each have a plurality of electronic components mounted thereon and that are accommodated within the casing, a display, and a battery.
Meanwhile, with the recent full scale arrival of an ubiquitous network society there has been an increasing demand for downsizing and low-profiling of electronic devices. With a structure such as one seen in a mobile phone in which components including a plurality of component built-in modules, a display, and a battery are accommodated within a preliminarily prepared casing, it is becoming difficult to realize further low-profiling.
On the other hand, Patent Document 1 discloses a configuration in which, in at least a part of a resin casing including an upper casing and a lower casing, there is a built-in and sealed component built-in module having an electronic component mounted on a wiring substrate. In this Patent Document 1, by having at least one of several component built-in modules built into the resin casing, the space inside the casing can be reduced and further low-profiling can be achieved.
Patent Document 2 discloses a structure that enables low-profiling by sealing one surface of a substrate with an electronic component mounted thereon, and treating one surface (bottom surface) of a component built-in module as a substrate and the other surface (top surface) as a resin sealing surface.